I realize why "Revert to Saved" is grayed out for new documents, but really, there's only one thing a user could possibly be trying to do when clicking this command on a new document. Just restore the document to a blank canvas with the original dimension setting.
To recover a corrupted .cdr file containing a CorelDraw drawing online: Press the Select file button and select a CorelDraw CDR file. Enter your email address. Enter the captcha code. Press the Continue button. Wait for the file to be recovered. Download the recovered CorelDraw drawing.